1. Field of the Invention
The invention generally relates to a gauge assembly that is capable of auto-calibrating and a method of calibrating a gauge assembly.
2. Background of the Invention
Instrument cluster gauges must be calibrated to insure the accuracy of the gauge. Currently, calibration of instrument cluster gauges is done externally. This type of calibration requires the use of manufacturing floor space, represents a significant financial investment, and requires service and maintenance routines.
Referring to FIG. 1, a prior art gauge calibration system is shown generally at 10. An instrument cluster 12 is mounted within a fixture 14. A vision system 16 includes a digital camera 18 and lens 20. The camera 18 communicates with a host computer 22 via a camera video and control harness 24. The host computer controls the camera shutter (not shown), and processes the images from the digital camera 18. The host computer 22 also controls the instrument cluster 12 via a communication interface 26 that allows the instrument cluster 12 and the host computer to communicate.
The digital camera 18 takes an image of the gauges on the instrument cluster 12. Simultaneously, the host computer 22 sends a signal to the instrument cluster 12 simulating an input to the gauges. The host computer 22 then compares the actual position of the needle pointer (not shown) of the gauges on the instrument cluster 12 with the input signal and calibrates the gauges to accommodate for any error.
As previously stated, this type of calibration is costly and takes up time and space. Therefore, there is a need for an instrument cluster that is capable of internal auto-calibration and a method of auto-calibrating.